Whole-home duct cleaning
Dryer vent cleaning
Camera inspection
Sanitizing & deodorizingWhole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents
That "$99 whole-house special" is a bait ad - the real number appears once they are in your hallway, or the "clean" is a shop-vac at the register. We photograph the inside of your ducts before and after instead.
Fast, Reliable Duct Sealing Across Highland Park
Duct sealing in Highland Park typically runs between $450 and $1,200 for a full system, depending on how much of the ductwork we can reach. Most jobs are done in a single day with no demolition. If you’re losing conditioned air through gaps in aging sheet metal, or if certain rooms never seem to reach the temperature on the thermostat, sealing the ducts is the fix that pays for itself in lower bills and more even airflow. We know these houses because we’ve worked inside hundreds of them across Highland Park, from the flats around Figueroa to the hillside streets above York Boulevard. Call (626) 469-5477 for a written quote before any work starts.
Why Hollis Air Duct Pasadena Is Highland Park’s Preferred Duct Sealing Company
Highland Park homeowners call us for one reason more than any other: we write the price down before the van shows up, and that number doesn’t move. Roy Castellanos leads our Duct Sealing team, and every technician who enters a home is background-checked and uniformed. You’ll know who’s walking through your door before they arrive.
We stock mastic, mesh tape, and replacement sheet metal locally so we’re not ordering parts from a warehouse while your registers sit disconnected. That matters on pier-and-beam bungalows where crawlspace access takes time and the job needs to be finished before evening. Our 365-Day Done Right Promise is written into every invoice: if a sealed seam fails within a year, we come back and fix it at no charge. Not a renegotiation, not a service fee. A free second visit, included.
Phones are answered by a live person, 24/7. You call, a human picks up, and you get a straight answer.
Styles & brands we work with
HVAC Duct Sealing in Highland Park
HVAC Duct Sealing in Highland Park addresses the joints, seams, and pinholes in metal ductwork that leak conditioned air before it reaches your registers. The problem is particularly visible in this neighborhood’s pre-1950s housing stock, where original sheet metal was sized for gravity furnaces, not modern forced-air blowers. When a modern system pushes air through those older ducts, the pressure finds every gap. You lose airflow, the system runs longer, and rooms at the end of the longest trunk lines stay uncomfortable. Sealing those leaks with mastic and aluminum tape brings the system back into balance. Expect to pay $450 to $1,200 for a full-system seal, and we’ll always write that number down before we begin.
Accessible Duct Sealing
Most Highland Park bungalows have exposed ducts in crawlspaces, attics, or utility closets. That’s actually good news: it means we can reach the majority of seams without opening walls. We seal what we can see and reach, and we’ll tell you plainly if a section is boxed in and can’t be reasonably accessed.
Whole-System Approach
We don’t seal the easy-to-reach trunk line and call it done. Highland Park homes with pier-and-beam foundations often have branch runs in the crawlspace that carry more leakage than the trunk. Skipping those leaves half the system leaking. We check every accessible run, not just the ones visible from the access door.
Duct Repair in Highland Park
Duct Repair in Highland Park goes a step beyond sealing: it means replacing damaged sections, reconnecting separated joints, or patching holes where rust has eaten through old galvanized steel. In a neighborhood where many homes sit on hillside lots with east-facing exposure, we regularly see rust-through pinholes from decades of temperature swings and the fine grit that blows down from the Arroyo Seco. The repair involves cutting out the compromised section and fitting new sheet metal to match, then sealing the connections. Repairs run $150 to $450 per section depending on access and duct size. A full repair plus sealing job on an older Highland Park home typically lands between $600 and $1,300.
Joint Reconnection
Older duct systems are held together with slip joints and sheet metal screws. Over 70 to 100 years, those joints pull apart, especially in crawlspaces where soil shifts during wet winters. We reconnect separated sections, align them properly, and seal the seam so they don’t separate again from normal vibration.
Rust and Corrosion Repair
Craftsman-era ducts weren’t always galvanized on the inside. Decades of condensation from air conditioning cycles create rust that eventually opens pinholes and small tears. We remove the rusted section and replace it, then check the surrounding duct for the same problem so you’re not chasing leaks one patch at a time.
Trusted Brands We Service in Highland Park
The equipment you already have matters less than how well we work on it, but it helps to know we run professional-grade tools from Rotobrush and Nikro on the cleaning side, and install filtration products from Honeywell and Aprilaire when your system needs better particle capture. We keep mastic, mesh, and common sheet metal sizes on the truck, which means we’re not leaving a Highland Park job half-done while parts come from a warehouse. If we find a Honeywell media cabinet that should be reseated, or an Aprilaire filter slot that’s warped and leaking, we can address it on the spot. That’s a faster turnaround and a tighter system on day one.
See the difference
Before
After
Before
After
Before
AfterCommon Duct Sealing Problems We See in Highland Park Homes
- Original undersized ducts on pre-1950s homes: Craftsman and Spanish Colonial Revival houses were often built with ducts sized for gravity heat. When a modern HVAC system is installed, the blower pressure exposes leaks that a gravity system never did. Sealing every accessible seam is the only way to get rated airflow to distant rooms.
- Branch runs ignored in pier-and-beam crawlspaces: The ducts easiest to reach are the trunk lines. The branch runs that snake through tight crawlspace corners are where a lot of Highland Park leakage lives. We inspect and seal those too, not just what’s visible from the access hatch.
- Hillside homes above York Boulevard pulling in more grit: East-facing slopes with little tree cover collect more wind-blown dust and freeway particulate. That grit works into joints and accelerates wear on older sheet metal. Sealing slows the intrusion and keeps the system cleaner between service visits.
- Asbestos-wrapped ducts in older Craftsman homes: Some original ducts have asbestos insulation wrap. We do not disturb that material. We can usually seal accessible seams without moving the wrap, and when we can’t, we’ll tell you before any work starts and recommend a specialist. The goal is a sealed system, not a hazardous one.
Pricing for Duct Sealing in Highland Park, CA
Here are straight numbers for Highland Park. A full-system duct seal on a typical 3-bedroom bungalow runs $450 to $800 when ducts are accessible from a crawlspace or attic. Larger homes, homes with multiple systems, or homes with difficult access run $800 to $1,200. Individual duct repairs – reconnecting a separated joint, replacing a rusted section – run $150 to $450 per section. The honest variables are access, linear feet of duct, and how much of the original system is still sound. You’ll get a written price before work begins, and that price is what you pay. Call (626) 469-5477 for a free estimate on your specific system.
We Also Serve Cities Near Highland Park
While this page focuses on Highland Park, our crews also work in Pasadena, Glendale, Downtown Los Angeles, and Burbank. If you’re just over the border in one of those cities, call (626) 469-5477 and we’ll confirm availability. We schedule intentionally so we’re never stretched thin across too many service areas in one day.
Serving Highland Park, CA - Our Local Coverage Area
We’re based in the Highland Park area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Duct Sealing in Highland Park
Yes, sealing reduces the volume of dust entering through return-side leaks, which is the main path for outside particulate in Highland Park homes near the 110 and the Arroyo Seco. Sealed return ducts pull air from inside the home rather than sucking dusty air directly from the crawlspace or attic. You’ll still see normal household dust, but the fine, reddish-brown grit that settles on window sills should drop noticeably. For an exact assessment of your system, call (626) 469-5477.
In most cases, yes. Highland Park Craftsman homes typically have ducts in the crawlspace, attic, or utility closet, not buried in interior walls. We can reach and seal the overwhelming majority of seams without demolition. If a duct is genuinely enclosed, we’ll tell you before quoting and give you the honest options. Call (626) 469-5477 and we’ll walk through what’s accessible in your specific floor plan.
East-facing hillside homes with limited tree cover take direct wind from the canyon and freeway corridors, which pushes more fine particulate into return vents. That exposure is specific to the upper streets of Highland Park, and it means your returns accumulate debris faster than homes on the flats below. Sealing return-side leaks and checking filtration – often a Honeywell or Aprilaire media cabinet – is the right first step to slow that accumulation. We can inspect your system and give you a written recommendation.
Duct sealing alone won’t fully fix a poorly designed or undersized system, but it usually reduces the imbalance significantly. When supply-side leaks bleed air into the crawlspace or attic before it reaches the upstairs registers, those rooms starve. Highland Park’s hilly lots make this worse because longer duct runs have more joints to leak. We’ll seal what’s accessible and tell you honestly if further rebalancing or duct modification is needed. Call (626) 469-5477 for an evaluation.
Yes, we can seal only your unit’s ductwork. In Highland Park fourplexes and duplexes, each unit typically has its own duct runs, even if the crawlspace or attic is shared. We will not touch a neighbor’s system without their own service agreement. What we can’t fully control is cross-particulate from neighboring units’ unsealed returns or dryer vents, but sealing your own system still reduces the air migrating through shared wall cavities. We’ll give you a written scope that covers only your unit before any work begins.
Written by Roy Castellanos, Owner at Hollis Air Duct Pasadena, serving Highland Park and surrounding neighborhoods.